Method and apparatus for loading internal gears



Dec. 5, 1961 T. s. GATES ETAL 3,011,410

METHOD AND APPARATUS FOR LOADING INTERNAL GEARS Filed Oct. 51, 1955 4Sheets-Sheet 1 A? a 2, 4 l. 91'

W, I 4W f J 0 I ii I hv INVENTORS THOMAS S. GATES. ALMARON AE TZLER.

BYMmffya WTHSRNEYS Dec. 5, 1961 T. s. GATES ETAL METHOD AND APPARATUSFOR LOADING INTERNAL GEARS Filed Oct. 31, 1955 4 Sheets-She I I /3 J 26m A A Pi Z7 33 l NVENTOR. -32 THO/{4A8 s. GATES.

AL MARON KETZLE/il BY 5 k 1 ATTORNEYS METHOD AND APPARATUS FOR LOADINGINTERNAL GEARS Filed Oct. 51, 1955 Dec. 5, 1961 T. s. GATES ETAL 4Sheets-Sheet 5 IN VENTOR. THOMAS 3. GA TES. ALMARON KETZL whim 'ATTORNEYS Dec. 5, 1961 T. s. GATES ETAL 4 Sheets-Sheet 4 Filed Oct. 51,1955 INVENTDR. THOMAS S. GATES. BYWARON KETZLER.

ATTORNEYS United States Patent Cfiice 3,011,410 Patented Dec. 5, 1961METHGI) AND APPARATUS FOR LOADING INTERNAL GEARS Thomas S. Gates, GrossePointe Woods, and Almaron H.

Ketzicr, Grosse Pointe Farms, Mich, assignors to National Breach &Machine Company, Detroit, Mich., a corporation of Michigan FiledOct. 31,1955, Ser. No. 543,763 8 Claims. (Cl. 90-1) The present inventionrelatesto an improved method and apparatus for loading internal gears on a gearshaving machine, the apparatus being entirely automatic in itsoperation. The invention further contemplates, as an important feature,a novel control of the engagement of a cutting or finishing tool with aformed internal gear blank to be finished, whereby the tool andworkpiece will unfailingly be in proper meshing relation at the time ofinitiation of actual cutting or finishing by the tool. In general, theinvention provides a novel and improved sequence of operations, and anovel and improved combination of mechanisms to perform them, by whichan internal gear blank is loaded on a rotary finishing machine, finishedand unloaded in an entirely automatic fashion, from beginning to end.

Consistent improvements in rotary gear shaving machines during recentyears have greatly increased the efficiency and productivity of suchmachines, in respect to output rate, to the extent that their productionis now restricted below optimum capacity by the capacity of availablemeans, manual, semi-automatic or fully automatic, to load the gears intothe machine and remove the finished product. In the case of a machinefor shaving internal gears, the handling procedures involve thepresentation of the gear to be finished in'axial alignment With aholding member or chuck, the axial displacement of the gear into suchchuck, the rigid clamping of the gear therein and, following themachining phase, a reversal of these operations to discharge the shavedgear.

If performed manually, this handling procedure would require an amountof time approximating that of the actual shaving operation, and it isevident that automatic provisions which will materially reduce such atime expenditure are highly desirable, indeed. 7

It is therefore a general object of the invention to provide an improvedmethod and apparatus for loading internal gears to a gear shavingmachine in an entirely automatic fashion and in the most expeditious andefficient way, to the end that the production rate of the shavingmachine shall be correspondingly improved.

More specifically, it is an object of the invention to provideapparatus-which Will advance and align an internal gear to be shavedwith a rotatable, positively driven holding chuck, which will shift thegear axially from the advancing means into the chuck directly followingthe presentation of the gear at the latter, and which will positivelyclamp the gear in the chuck for the ensuing shaving cycle.

In accordance with the invention, the provisions for advancing andpresenting a gear at the rotatable holding chuck may take alternativeforms, having in commonthe feature of inclined gravity ways or chutesfor the in-feed and out-feed of rough and finished gears, respectively.A leading gear is taken from the in-feed chute by a pneumaticallypowered reciprocatory transfer unit, which advances the gear into axialalignment with the chuck, and also, in accordance with one embodiment,receives and returns a finished gear to the vicinity of the dischargeway or chute after the shaving operation. In each adaptation of theinvention, the gear to be shaved is displaced from the transfer unitinto the machine chuck by a pneumatically powered ram, which swings intoand out of axial alignment with the chuck for this purpose.

The rotatable chuck of the apparatus has associated therewith aplurality of angularly movable clamps and a plurality of axially movablestripper rods; these respective members are actuable to clamp a gear inthe chuck following the operation of the loading ram, referred to above,and to eject the finished gear from the chuckafter the shaving cycle.Individual pneumatic plungers are employed to actuate the respectivesets of clamping and ejecting members, the plungers being received inpneumatic cylinders which are pressurized in predeterminedly timedrelation; and provision is made in the operating connections between therespective angularly shiftable clamping members and the axiallyshiftable ejecting plungers to permit their necessary rotation with thechuck with which they are associated without imposing any significantrotative torque on the plungers which power the same.

In accordance with one embodiment of the invention,

the finished gears are ejected axially from the chuck directly into agravity discharge chute or way, along which they proceed to a suitablereceiver. In accordance with an alternative form, the ejector pins shiftthe finished gear into the transfer unit or head which initiallypresented it to the chuck, and the transfer unit returns the finishedgear to a discharge way or chute adjoining the feed-in way or chute; Inthis position, a special transfer plunger operates to ejecct thefinished gear from the transfer unit referred to into the dischargechute, at the same time loading the transfer unit with another gear tobe shaved from the feed-in chute.

Considering the structure of the rotary work holding chuck morespecifically, the invention provides a chuck which has associatedtherewith a plurality of radially swingable clamp arms spaced from oneanother about the periphery of the chuck, which is internally recessedin a proper size to snugly receive the internal gear to be shaved. Eachclamp arm is mounted on an elongated rod which has camming engagementwith the chuck proper, whereby axial movement of the clamp arm rod willoccasion an angular swing of the arm inwardly over an exposed outer faceof the gear. This set of clamp arm rods is operatively mounted to therear'of the chuck on a recipro'catory head, and this head is controlledin its actuating movements, to effect the cam operation referred to, bya pneumatic cylinder.

The chuck is also provided with a plurality of circumferentially spacedejector pins, which extend axially through recesses or bores in thechuck to accommodate the same. Axial shifting of the pins toward theopen mouth of the chuck causes them to engage and eject the gear carriedin the latter, which has been-previously un clamped by operation of thecam provisions mentioned in the preceding paragraph. The pins areconnected at their rear to a suitable operating head which has anaxially fixed but rotatively loose conection on a control plunger, bywhich the pins are given their axial movement. The plunger in questionconnects rearwardly to a pneumatic piston whereby operation of theejector unit is controlled in timed relation to operation of the gearclamp arms. The loose connection prevents rotation of the plunger andpiston, yet enables the ejector pins to rotate with the chuck in whichthey slide axially.

As indicated by the foregoing, it is an object of the invention toprovide an improved gear shaving method, featuring the sequence ofadvancement of individual gears into axial alignment with a work holderor chuck, displacement of the gear into the chuck, clamping of the gear,followed by shaving of the gear, unclamping and ejection of the gear anddischarge of the finished gear, either bygravity or by a positivemechanical transference.

As an important feature of this method, as well as the combinedapparatus for performing it, the shaving machine incorporates provisionwhereby the engagement of its cutter with the gear to be shaved iseffected after an initial rapid stroke, then a slower advance whichactually contacts the cutter with the gear. This advance is accomplishedunder pneumatic or hydraulic pressure, in a yieldable fashion inaccordance with the invention, and if a proper meshing relation of thecutter and gear does not result, the advancing stroke is interrupteduntil there is a proper mesh. It is contemplated that the cutter begiven a jogging push under yielding force at the end of its slowadvance, i.e., be imparted slight momentary pulsatory pressureincrements while yet in engagement with the end of the gear, whereby ita mesh with the gear teeth does not occur at once, it will take placemomentarily thereafter. This is done by a pressure by-pass unit whichlimits the end pressure on the cutter. It is also within thecontemplation of the invention to provide means, for example in afurther refinement of a pressure controlled device which affords thepulsatory effect described above, to reverse the movement of the cutterin the event it fails to mesh properly with the gear, causing the cutterto back off for a second stroke or further repeated strokes towards thework.

With these and other objects in view, the invention resides in the novelfeatures of construction and combinations and arrangements of parts asmore fully hereinafter set forth.

In the drawings:

FIGURE 1 is a face view of an internal gear shaving machineincorporating the improved apparatus for loading gears according to oneembodiment of the invention;

FIGURE 2 is a view generally in side elevation, but partially in sectionalong line 2-2 of FIGURE 3, of the machine of FIGURE 1;

FIGURE 3 is a top plan view of the equipment;

FIGURE 4 is an end view of a generally similar internal gear shavingmachine incorporating loading apparatus in accordance with amodification of the invention;

FIGURE 5 is a top plan view of the machine of FIGURE 4;

FIGURE 6 is a fragmentary view in axial section through a work holdingchuck and associated gear clamping and ejector means of the apparatus;

FIGURE 7 is a fragmentary view in end elevation of the chuck structureof FIGURE 6, viewed from the right of that figure; and

FIGURE 8 is a fragmentary diagrammatic view illustrating a proposedpressure bypass valve unit for the control of the cutter of the gearfinishing machine in its advance into mesh with a gear blank held in thechuck of the apparatus.

Referring first to FIGURES 1, 2 and 3 of the drawings, they depictgeneral structural components of a machine for shaving internal gears,generally designated 10, with which the improved loading apparatus 11 ofthe invention is associated. This machine operates on the crossed axisprinciple, although a coaxial relationship of its work holder andcutting tool is shown in the drawings for the sake of simplicity. Muchof the equipment appearing in FIGURES 1, 2 and 3 is entirelyconventional, including a frame 12; a slide assembly 13, carrying acutter head 14 and its associated spindle 15 and cutter 16; and a worksupport 17 in opposed relation to the cutter head. In accordance withthe invention, axially aligned inner and outer pneumatic cylinders 18,19, respectively, are fixedly associated with the work support 17 toproject outwardly thereof, in axial alignment with a rotatable chuck orwork supporting head 20 of the work support 17. A pneumatic cutter slidecylinder 21. controls movements of cutter head 14 toward and from chuck20.

The chuck 20 is powered through a gear connection, hereinafter referredto, from an electric motor 22 mounted on the machine frame, and theactual machining operation to shave internal gears is a conventionalone.

The reference numeral 23 denotes a pivotally and axially movable ramwhich is carried on a plunger 24 piloted in a tubular casting 25 atopthe work support 17. The ram includes an axial pushing head 26 carriedby a rigid radial arm 27 on the outer end of plunger 24. At its oppositeextremity, the plunger 24, or suitable piston thereon (not shown), isreceived in a pneumatic cylinder 28 attached to the mounting casting 25.Alternate actuation of the plunger in opposite directions obviouslyoccasions corresponding axial movements of pushing head 26. A furtherpneumatic cylinder 29 is mounted to casting 25 to extend laterallytherefrom. Cylinder 29 similarly receives a piston or plunger which isappropriately connected operatively, as by rack and segment elements,for example, with the plunger 24. Accordingly, reverse movements of theplunger in cylinder 29 occasion oscillating movement of pushing head 26about its plunger 24 as an aXis through a predetermined limited angularswing. As illustrated in FIGURE 1, this swing is of sufiicient extent tobring the pushing head 26 into and out of axial alignment with the workrecess or chuck 2% Internal gears G to be shaved are gravitationallysupplied in sequence by an inclined way or chute 30 which, asillustrated in FIGURE 1, lies in a plane paralleling and slightlyforwardly of the outer face of chuck 29. Gears G are discharged fromchute 30, under the control of a suitably actuated, periodically actingescapement or metering element 30' associated with chute 3t into anarcuate transfer cradle 31 which is reciprocably carried by a supportingframe, including pneumatic plungers 32 received in a pneumatic controlhead or housing 33. Appropriate provision is made therein to reverse thedirection of movement of transfer cradle 31 in timed relation to theoperation of other components of the machine, which are also controlledautomatically by appropriate pneumatic valving provisions which willsuggest themselves to those skilled in the art.

As received in cradle 31, a gear G to be shaved is in the horizontalplane of the axis of chuck 26*, so that movement of the cradle to theright, as viewed in FIGURE 1, will transport and present the gear G inaxial alignment with the chuck. I'I'he pushing head 26 has been swungdownwardly prior to this time in axial alignment with the gear, underthe control of the ram up-down cylinder 29, whereupon axial movement ofhead 26 under the control of ram in-out cylinder 28, will shift gear Gfrom cradle 31 into the chuck 29, where it is positively clamped inplace by the provisions later to be described.

The reference numeral 35 generally designates a gravity discharge chute,the inner receiving end 3 6 of which is disposed immediately beneath themouth of chuck Zll in a vertical plane which includes the line ofmovement of transfer cradle 31. After discharge from chuck 29 by theprovisions to be described, the finished gears descend into chute 35 androll therefrom to a disposal point or collector.

A second adaptation of the invention, in regard to the generalprovisions for supplying gears G to be shaved and for removing theshaved gears, is illustrated in FIGURES 4 and 5 of the drawings. In thisform the receiving end of the discharge chute by which finished gearsare removed is located to a side of the chuck 20, in side by siderelation to a feed-in chute for gear blanks. Components of the equipmentof FIGURES 4 and 5 which have structural features or functions in commonwith the features or functions of components depicted in FIGURES 1, 2and 3 are designated by corresponding reference numerals and, in theinterest of simplicity and brevity, will not be further described. Itmay be noted that in the form of FIGURES 4 and 5 the cylinder 29 whichcontrols oscillation of ram 23 is vertical.

The gear feed and discharge unit of FIGURES 4 and 5 is generallydesignated 37. It includes a feed-in way or chute 38 similar to thechute 30 of FIGURES 1, 2 and 3, the inner end of the chute 38 includinga circular area which is in axial alignment with the internal diameter39 of a band-like transfer head 40, when that band or head is in itsretracted position to the left, as viewed in FIGURE 4, ready to receivea new gear G to be shaved as well as to discharge a gear previouslyshaved. Transfer head 40 is reciprocated by a plunger frame 41 receivedin a pneumatic control chamber 42 similar to the chamber 33 of FIGURESl, 2 and 3, in which its reversals of movement are governed in timedrelation to the incidents of the operation of the apparatus.

As in the first embodiment, movement of head 49 to the right transportsand positions a gear to be shaved in axial alignment with the chuck 20,after which the gear is placed in the chuck by pushing head 26, lockedtherein, shaved and ejected in the manner referred to previously.However, in this instance, ejection of the finished gear by theprovisions to be described causes the same to be displaced into thetransfer head 40, the head having partaken of a second stroke intoalignment with the chuck to receive the ejected gear. So repositioned inthe transfer head 40, the next movement of the latter conveys thefinished gear to the left, i.e., back to its starting point.

By reference to FIGURE 5, it will be noted that a pneumatically operatedtransfer cylinder 43 is appropriately mounted in axial alignment withthe transfer head 40in this last mentioned position. Cylinder 43contains a piston (not shown) which is operated in timed relation to theother parts, and its function is to effect the simultaneous transfer ofgears to be shaved into, and shaved gears out of, the head 43. Thus, thepiston in cylinder 43, in displacing unshaved gear G out of feed-inchute 38, i.e., to the right as viewed in FIGURE 5, causes that gear asit is received in transfer head 40 to eject a finished gear from thehead into the discharge chute 44, along which it gravitates to adisposal point or collector.

Turning now to FIGURE 6 of the drawings for structural details of thechuck gear clamping and ejecting provisions according to the invention,the embodiment of the invention presented for the purpose ofillustration provides a chuck proper 2t} fitted with an annular adaptorring 45 bolted thereto. As illustrated in FIGURES 6 and 7, this ring hasthree equally spaced recesses 46 in its exposed forward edge whichreceive and accommodate movement of the individual angularly shiftablegear clamping dogs 47. Each dog 47 has a reversely directed clamp nose48 engageable with the outer face of a gear G, and the dog is carried asa rigid forward nose piece of an angularly and axially shiftableoperating rod 49, each rod 4? being slidably received in an individualbore 50 extending through the chuck proper 26. The rod 49' is providedwith a shaped cam slot 51 in the form of a modified helix, which slotreceives a fixed pin 52 carried by a plunger 53 in a bore 54 of thechuck. It is evident that upon axial movement of the rods 4-9, the clampdogs 47 of the latter will be moved axially to and from the outer faceof chuck adaptor 45, and a gear G therein, as well as to swing into tipiloted in bores 66 in the rotatable cage or frame '56 of the chuck 20.

A plurality of elongated, forwardly projecting ejector rods 68 areprovided for the purpose of stripping finished gears G from the chuckadaptor 45. In the illustrated form, there are three of these rods,spaced equally in the circumferential sense, and each is received in acorresponding bore 69 which extends through an inner radial flange 70 ofthe chuck proper 2i Forwardlyof this flange, the adaptor is providedwith correspondingly spaced rounded grooves 71 in alignment with therespective bores 69; so that the ejector rods 68 are free to move andstrip a gear G from the chuck when actuated to the right as viewed inFIGURE 6. The rear ends of the ejector or stripper rods 63 are afiixedto a header plate 72 mounted centrally on an actuator plunger 73 of theunit. This is a loose rotatable connection, allowing header plate 72 androds 68 to rotate with chuck 20 without imparting any rotative torque toplunger 73. Header plate 72 is provided with apertures 74 to accommodatethe heads of bolts 75 which secure the other rotatable shaft header 62to its tubular shaft 61.

The pin actuator plunger 73 extends axially through the bore 76 ofhollow shaft 61, in which it is mounted by an anti-friction bearing 77.Tubular shaft 61 is in tuprn journaled by a ball bearing assembly 78,the inner race of which is suitably clamped to the shaft, and the outerrace of the bearing assembly is clamped to and abutted at its rear bythe cup-like forward extension 79 of a tubular actuator 80 which isoperated pneumatically in the clamp cylinder 18 applied to work support17 (FIG. 2). The ctuating plunger 73 received in hollow shaft 61, andalso extending axially through actuator 73, is similarly actuatedpneumatically in the ejecting cylinder 19 of the apparatus.

It is of coursecontemplated that in the normal operation of the machinethe cutter 1 6 will not always engage on its inward stroke in accurateangular register with a gear clamped in head 20. It is thereforedesirable that provision be ma e to insure the proper entry of thecutter,

which is a conventional type having an annular series of cutting teeth,in meshed relation to the teeth of the gear blank, the end motion takingplace under limited end and out of position to overlap the gear face andclamp the same.

Chuck 2%) is secured by bolts to a hollow rotary mounting frame 56,which is in turn bolted at its rear to an elongated bearing tube 57appropriately journaled by roller bearings 58, and appropriately sealedalso, in the interior of the work support 17 of the machine. To thissleeve the necessary gear provisions, designated 59, are applied toeffect positive rotation of chuck 26 from the motor 22 as a prime mover.

Reciprocating movements of the clamp arm control rods 49 are in responseto axial movements of a hollow tubular shaft 61 which extends axially tothe rear through rotatable tube 57. A centrally apertured header plate62 is bolted to the forward end of hollow shaft 61, and a plurality ofequally spaced radial actuator bars 63, three in number in theillustrated unit, are in turn bolted to the header plate 62, so as toform in effect a radially extending spindle spider. The spindle bars 63are notched or bifurcated at 64 on their outer ends, these forkedportions straddling reduced portions of the respective clamp arm controlrods 4?. The rear ends of the rods 49 are pressure. Meshing will befacilitated by the use of a special cutter tooth form having a taperedentry nose which will lead the cutter into the gear Without undue clasheven if the angular alignment is not exact; however, in the alternativeor in supplementation of the use of a special cutter form, anarrangement such as is shown in FIG. 8, for controlling the cutterstroke may be employed. This will insure that the cutter is initiallypresented to the gear G under a controlled, low end pressure, withoutclash.

As illustrated in PEG. 8, a suitable control cylinder 81 is mounted infixed relation to the cutter actuating cylinder 210i FIGS. 2 or 5, andthe internal bore 82 of cylinder $1 is appropriately connected with thepressurized side of cylinder 21. A control plunger 83 slidably mountedin cylinder bore 82 is thus subject to the pressure on the piston (notshown) in cylinder 21 which urges cutter 16 for its operating stroke.

A coil spring 84 is disposed in cylinder 81 between plunger 83 and theclosed end of the cylinder and resists movement of the plunger underthis pneumatic force. The plunger is adapted to uncover a by-pass orbleeder passage 85 leading from control plunger bore 82 in the event thepressure on the plunger exceeds a value predetermined by the strength ofthe spring.

Accordingly, in the event the cutter, in being pneumatically advanced onits operating power stroke, should fail to mesh in the desired degrewith the gear G, so that the end interference gives rise to an increasein pressure in cylinders 21 and 81, plunger 83 will yield to the left.Under sufiicient pressurization, this exposes the by-pass 2' passage 85and bleeds the overpressure, whereupon spring 84 restores the plunger tothe right.

The by-passed air may be voided to atmosphere if desired, or it may bereturned to the power cylinder 21 on the side of its piston (not shown)which will tend to cause the piston to take a slight shift to the right.An ensuing application of pneumatic power to cylinder 21 will reengagethe cutter with the gear G at a different point. An early automaticengagement without damage to gear or cutter is insured by the thusproduced jogging action of cutter 16.

It is believed that the operation of the improved apparatus will beunderstood from the foregoing description. In the embodiment illustratedin FIGS. 1, 2, and 3, gear G gravitates towards chuck 26 in chute 36,from which they are received by the transfer cradle head 31 when thelatter is in its lefthand position. Suitable valving .(not shown) withinhousing 33 controls the horizontal shifting of cradle 31 to the right toposition the gear G in axial alignment with the chuck 20. The pushinghead 26 now swings downwardly, in a plane paralleling the movement oftransfer cradle 31 into axial alignment with chuck 2 0, under thecontrol of a piston or plunger (not shown) in pneumatic cylinder 2%; andupon reaching alignment with the chuck, the pushing arm 27 of head 28 isshifted inwardly of the chuck by ram in-out cylinder 28. Head 26displaces a gear G from cradle 31 into the chuck 20 following which head26 returns and retracts upwardly, the gear is clamped in the chuck, ismachined by cutter 16, is unclamped and is ejected from the chuck in amanner hereinafter set forth. Pushing head 26 again returns at thispoint into axial alignment with the chuck, serving as a backstop for theejected gear.

Upon ejection from the chuck, the gear gravitates, in the embodiment ofFIGS. 1, 2 and 3, to a discharge zone along the chute 35.

The embodiment illustrated in FIGS. 4- and differs from that justreferred to solely in respect to the manner in which unfinished andfinished gears are handled. In this case, the gear blanks are laterallytransferred from the feed-in chute 38 into the ring-like or band-liketransfer head 40 by means of an auxiliary transfer cylinder '43.Transfer head 49 shifts the gear into axial alignment with chuck 2.0 ona first stroke, returning to the left to allow the cutter 16 to operate.Following the finishing of the gear by cutter 16, the head 40 againmoves. It is again hydraulically shifted to the right, under the controlof pneumatic valving (not shown) in housing or chamber 42. It therereceives a finished gear ejected from the chuck and then returns to theleft to its original position. Ensuing operation of the laterally actingtransfer unit, which is powered by cylinder 43, causes an unfinishedgear blank to be shifted into the head 4%}, in turn ejecting a finishedgear G from the head 4%, from which it gravitates along discharge chute44 to a disposal or discharge point. Upon the reception of a gear blankin chuck 20, the clamping dogs47 on rods 49 are swung inwardly toclamping position and are axially engaged with the outer side of thegear blank upon axial move ment of the rods as to the left, as viewed inFIG. 6. Swinging of the dogs is effected by the camming engagement ofthe rod slots 51 with the fixed pins 52 of the chuck (FIGS. 6 and 7).The cutter 16 then engages the gear blank, initially under the yieldablecontrol of the by-pass provisions shown in FIG. 8, whereupon the gear isfinished in a conventional fashion.

Upon completion of the machining, the dogs 47 unclamp the gear G as rods49 are shifted to the right, and move to a radially withdrawn position.Ejector pins or rods 63 now shift to the right as viewed in FIG. 6 and:shift the gear G out of chuck 24), against pusher head 26 and onto thetransfer head, whereupon the pins 68 are retracted. Transfer head-4Q ofthe embodiment of FIGS. 4 and 5 takes a second stroke in the cycle, intoalignment \with chuck .20 to receive the gear as distinguished from 8the single feed stroke of the head 31 in the form of FIGS. 1, 2 and 3.

The loose rotative and axially fixed relation of the pin or rod carryingheader plate '72 on central plunger 73 enables the plate and rods 68 torotate with chuck 20, without rotation of plunger 73. On the other hand,the tubular shaft 61, on which the clamp actuating rods 49 are mountedby rotatable plate 62, may rotate in its rear ball bearing assembly 78,the outer, rotatively fixed race of which assembly is operated axiallyby a rotatively fixed, axially movable actuator 79. This actuator is inturn operated under the control of the clamping cylinder 18; theejecting rods 49 are similarly operated through plunger 73 under thecontrol of the pneumatic ejecting cylinder 19.

Reference has been made above to the fact that pressure bypassed in thecontrol valve structure 81 may be voided to atmosphere or may bereturned to the power cylinder 21, for a repetitive stroke cycle of thecutter involving strokes of substantial length, as compared to thetapping or jogging effect otherwise produced by the bypass action. It isof course evident that provisions to these ends, which no doubt willsuggest themselves in one form or another to those skilled in the art,may be incorporated individually and separately in the apparatus.However, there is shown in FIGURE 8 an arrangement for combining thesame for an option in this regard. In FIG- URE 8, the bypass passage 35is shown as being connected through a nipple 86 with a three-Way valve87 which has a pressure fitting 88 leading to atmospheric pressure, orto a suitable receiver (not shown) in the event hydraulic pressure is tobe employed to actuate the machine. Valve 87 has a further dischargefitting 89 which, in a pneumatic installation, leads to a suitablediaphragm type actuator t). A control rod 91 extends from thespring-biased diaphragm (not shown) of the unit 90. The control rod 91has a pivotal connection at 92 to a contactor of a switch which controlsthe flow of current in an electrical circuit which governs theapplication of pneumatic or bydraulic pressure to the actuator forcutter 16. As contemplated herein, this circuit may include arrangementsto reverse the action of the pressure liquid in cylinder 21 and therebycreate a reversal of the stroke of cutter 16 when a contact ismomentarily made by switch contactor 93. Provisions to this end have notbeen illustrated, but will be obvious to those skilled in the art.

Supplementary provisions may be course be made in the gear loadingapparatus as generally described above for various control purposes. Forexample, it may be desirable for the purpose of adjustment, and toregulate the stroke of certain pneumatically controlled members, toprovide a unit such as is shown in FIG. 7 and generally designated 94.The purpose is to control the stroke of the piston in cylinder 29 whichoperates the ram 23 on the oscillatory movement of its radial arm 27. Tothis end, the unit 23 may consist of a rigid arm 95 atfixed to anoutwardly extending end of a plunger 96 which operates in cylinder 29.The arm carries at its top a laterally extending slide beam 97 which isguided in fixed brackets 98, and a member 99 adjustably clamped on beam97 carries a tappet 1610. This tappet is engageable at opposite extremesof the movement of plunger 96 with fixed stops 101, thus limiting theswing of ram arm 27, and enabling the swing to be accurately adjusted,so that the ram clamp head 26 aligns accurately with the chuck 20 in itsoperative loading position.

Provisions of this sort may also be made to control theclamping-unclarnping, axial movements of the ram; however, in theinterest of simplifying and clarifying the drawings, specificillustration of appropriate units, such as the unit 94 of FIGURE 7, hasbeen omitted from the remainder of the figures.

The drawings and the foregoing specification constitute a description ofthe improved method and apparatus for loading internal gears in suchfull, clear, concise, and

exact terms as to enable any person skilled in the art to practice theinvention, the scope of which is indicated by the appended claims.

What We claim as our invention is:

1. Loading apparatus for a gear finishing or like machine comprisingperiodically operating means receiving and positioning articles to befinished, said means including a longitudinally shiftable headtransferring said articles in axial alignment with and axially outwardlyof a rotatable work holder of said machine, a transfer memberperiodically engageable with an article aligned with said work holder bysaid transfer head, said member being mounted for swinging movement in avertical plane paralleling the direction of movement of said transferhead, and means to shift said transfer member axially inwardly towardsaid work holder to displace an article from said transfer head of saidpositioning means onto said work holder, said head guiding saidarticlein the displacement of the latter by said transfer member, saidreceiving and positioning means further including a gravitationalarticle feed chute having a discharge end posi tioned in lateralalignment with and on one side of said transfer head in a retractedposition of the latter, a gravity discharge chute having its receivingend in lateral alignment with said retracted position on the oppositeside of said transfer head, and an auxiliary transfer deviceperiodically operative to shift articles from said feed chute dischargeend onto said transfer head and from the latter onto said receiving endof said discharge chute.

2. A loading apparatus for a gear finishing or like machine comprisingperiodically operating means receiving and transporting articles to befinished into position in axial alignment with and axially outwardly ofa rotatable work holder of said machine, a transfer member periodicallyengageable with an article aligned with said work holder by saidtransporting means, and means to shift said transfer member axiallyinwardly of said work holder and transversely of the path of saidtransporting means to displace an article transversely from saidtransporting means onto said work holder, said transporting meansslidably guiding said article in the displacement of the latter "by saidtransfer member, and being formed to permit said engagement of thetransfer member with the article to so displace the latter.

3. Loading apparatus for a gear finishing or like machine comprisingperiodically operating means receiving and positioning articles to befinished, said means including a longitudinally shiftable headtransporting said articles into axial alignment with and axiallyoutwardly of a rotatable work holder of said machine, a transfer memberperiodically engageable with an article aligned with said work holder bysaid transporting head, and means to shift said transfer member axiallyinwardly of said work holder and transversely of the path of saidtransporting head to displace an article from said transfer head of saidpositioning means onto said work holder, said head slidably guiding saidarticle in the displacement of the latter by said transfer member, andbeing formed to permit said engagement of the transfer member with thearticle to so displace the latter.

4. Loading apparatus for a gear finishing or like machine comprisingperiodically operating means receiving and positioning articles to befinished, said means including a longitudinally shiftable headtransporting said articles into axial alignment with and axiallyoutwardly of a rotatable work holder of said machine, a transfer memberperiodically engageable with an article aligned with said work holder bysaid transporting head, said member 10 being mounted for swingingmovement in a vertical plane paralleling the direction of movement ofsaid transfer head, and means to shift said transfer member axiallyinwardly of said work holder to displace "an article from said transferhead of said positioning means onto said work holder, said head slidablyguiding said article in the displacement of the latter by said transfermember, and being formed to permit said engagement of the transfermember with the article to so displace the latter.

5. The improvement in a gear finishing or like machine, comprising arotatable work holder, and period'- ically operating means receiving andpositioning articles to be finished on said work holder, including meansreceiving and transporting articles to be finished into position inaxial alignment with and axially outwardly of said work holder, atransfer member periodically engageable with an article held so alignedwith said work holder by said transporting means, and means to shiftsaid transfer member axially inwardly of said work holder andtransversely of the path of said transporting means to engage anddisplace an article transversely from said transporting means onto saidwork holder, said transporting means slida-bly guiding said article insaid displacement of the latter by said transfer member, and beingformed to permit said engagement to the transfer mern'ber with thearticle to so displace the latter.

6. Apparatus in accordance with claim 4 in which said transfer memberincludes a ram mounted for axial and swinging movement about an axisparalleling and spaced from the axis of rotation of said work holder.

7. Loading apparatus in accordance with claim 4 in which said receivingand positioning means further in: cludes a gravitational article feedchute having a discharge end positioned adjacent and in gravitationalsup ply relation to said transfer head in a retracted position of thelatter, and a gravity discharge chute having its receiving end ingravitational receiving relation to said work holder.

8. Loading apparatus in accordance with claim 6 in which said receivingand positioning means further includes a gravitational article feedchute having a discharge end positioned adjacent and in gravitationalsupply relation to said transfer head in a retracted position of thelatter, and a gravity discharge chute having its receiving end ingravitational receiving relation to said work holder.

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